The present invention relates to a network system for connecting a digital copying machine and an external device through a data transmission line, for inputting and outputting image data therebetween, and digital apparatuses interconnected by a network.
Conventionally, a network system including a digital copying machine and external devices, such as a personal computer and a printer, interconnected has been known. Such a digital copying machine reads an image on a document by an image reading section (image taking section), and executes an image formation according to the read image data.
Such a digital copying machine performs not only a copying function, but also a plurality of functions, such as a printer function of forming an image according to image data input from the external device and a scanner function of outputting the image data read from the document to the external device, by sending and receiving the image data to/from the external device through a data transmission line.
However, the conventional network systems suffer from the following problems. Specifically, some digital copying machines do not have a large-capacity image memory for storing all the image data read by the image reading section. With a network system including such a digital copying machine which does not have a large-capacity image memory, the processing executable to the image data of the document read by the digital copying machine is considerably limited, and thus there is a problem that the functions of the devices constituting the network system are not used effectively.
In order to avoid such problems, U.S. Pat. No. 5,854,693 (Filed: Jan. 7, 1997, Date of Patent: Dec. 29, 1998) discloses an image forming system including an image forming apparatus, such as a digital copying machine, and a plurality of external devices (for example, a printer) which have image memories and are connected to the image forming apparatus through an interface. In this system, if the free space (available memory area) in the memory is less than a memory capacity necessary for reading a remaining document when reading the document in the image forming apparatus, the image data exceeding the free space is transferred to the image memory of an external device through the interface to record the image data.
However, with the above system, when the image data are sent to and recorded in the image memory of the external device through the interface more than one time, it is difficult to identify each image data and accurately retrieve each image data recorded in the image memory of the external device.
Moreover, with the above system, since the image data is divided and separately recorded in the image forming apparatus and the external device, it is necessary to call the respective divided image data and sort them in order when executing an image formation by gathering the divided image data. Thus, there is a problem that it takes a long time for the image formation.
An object of the present invention is to provide a network system and digital apparatuses interconnected by a network, capable of executing various processing on image data of a document read by a digital copying machine having no image memory by effectively using the function of each device and of easing a search for each image data and an image formation from the image data, by recording the image data of the document in an image memory of another external device within the network system to reduce the repetition of the reading of the image data from the document.
In order to achieve the above object, a network system according to the present invention detects whether there is a free space in an image memory of an external device, adds an identification data for identifying image data read from a document by a digital copying machine to the image data during an image formation according to the image data of the document in the digital copying machine, and records the image data with the added identification data in the image memory of the external device, which has a free space.
With the above system, the image data relating to an image formation in the digital copying machine can be recorded collectively with the identification data added thereto in the image memory of the external device within the network.
Therefore, even if the digital copying machine itself does not include an image memory having a sufficient capacity for recording the image data of the document, since the image data read by the digital copying machine is recorded in another device within the network after adding the identification data to the image data, it is possible to search for and call the image data easily by the identification data and execute the image formation by eliminating the necessity of reading the image of the document again in performing an image formation according to the same image data later. Thus, with this system, the image formation can be simplified, and the time taken for the image formation can be shortened.
In this system, the identification data preferably includes a user identification code (hereinafter referred to as the xe2x80x9cuser ID (identification)xe2x80x9d) for identifying an operator who operates the digital copying machine.
With this system, a user ID for identifying an operator who instructs the execution of an image formation according to the image data to be recorded in the image memory of the external device is added to the image data. Therefore, it is possible to identify the image data recorded in the image memory of the external device for the purpose of judging whether an image formation is available, on the basis of the user ID which is to be input first by the operator when performing an image formation.
Consequently, with the above system, it is possible to eliminate the process of additionally creating data for identifying the image data and facilitate a search for the image data recorded in the image memory of the external device.
In this system, when an image recording process for recording the image data in the image memory of the external device is not completed, it is preferred to arrange reading of the image data from the document in the digital copying machine and the image recording process to another external device to be executed again.
With this system, when the recording of the image data subjected to an image formation in the digital copying machine in the external device can not be completed properly due to some reasons such as a shortage of the free space in the image memory in the course of the process, the reading of the image data from the document in the digital copying machine is executed again, and the read image data is recorded in the image memory of another external device, which has a sufficient free space for the data volume. Thus, since the image recording process can be executed again without recording the image of a single image data over two image memories, the image data can be surely recorded.
In this system, the digital copying machine is preferably arranged to detect a free space in the image memory for each of a plurality of the external devices, according to a preset priority order.
With this system, the detection of a free space in the image memory of each of the external devices is performed according to the preset priority order. Hence, by setting the priority order for each external device by considering the convenience of the management of the image data, the image data can be recorded in a state suitable for the management in the external device. Consequently, with this system, the management of the recorded image data can be eased by the setting of the priority order.
In this system, it is preferred to arrange the digital copying machine to calculate a data volume of the image data of the document in advance and record the image data in an image memory having a sufficient free space for the calculated data volume.
According to this system, by calculating the data volume of the image data of the document in advance, the image data is recorded in the image memory having a free space sufficient for the data volume of the image data to be recorded.
This system prevents a shortage of a free space in the image memory in the course of the image recording process and ensures a completion of the image recording operation, thereby improving the operation efficiency of the digital copying machine.
In this system, it is preferred to compare a record period from the record time of the image data recorded in the image memory of the external device to the current time with a preset predetermined period (specified period), and selectively delete the image data whose record period exceeds the predetermined period.
With this system, the image data which has been recorded in the image memory of the external device in a period of time longer than the predetermined period is selectively deleted. It is therefore possible to prevent the memory area in the image memory of the external device from being occupied by unnecessary image data. Consequently, this system can use the image memory of the external device properly as the recording function of the external device.
For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings.